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"There were similarities that appeared to me," Clinton said

Clinton did not mention Melania Trump's prime-time address

Las Vegas (CNN)Hillary Clinton on Tuesday slammed the first day of the Republican National Convention as "surreal," comparing it to the "Wizard of Oz" while avoiding mentioning Melania Trump's plagiarism controversy.

Clinton, who didn't watch much of the convention proceedings because she was flying from Minneapolis to Las Vegas, told public service employees at the AFSCME convention in Las Vegas that she made the comparison after hearing about delegate protests on the floor and some of the speeches.

"I kept thinking, 'What's this like?' And then I thought, you know, when I was a little girl, I went to see ... 'The Wizard of Oz,' " Clinton said. "And there were similarities that appeared to me. Lots of sound and fury, even a fog machine, but when you pulled back the curtain, it was just Donald Trump with nothing to offer the American people."

Clinton added that speakers at the convention "spent more of their time attacking me and President (Barack) Obama rather than making any kind of argument about the future we want to build for our country."

One issue Clinton did not mention was Melania Trump's prime-time address, portions of which have been accused of being plagiarized from first lady Michelle Obama's 2008 Democratic convention speech.

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Clinton said speakers at the convention, which included a number of people who called for her to be jailed, said the proceedings proved that "Donald Trump may claim he is on the side of working people but his actions say otherwise."

Clinton was well received by the union organizers, whose head organization endorsed Clinton in October.

Trump was the focus of much of Clinton's remarks, including when the former secretary of state questioned why he has yet to release his tax returns.

"By the way, if you happen to know anybody, or run across anybody who is thinking about even contemplating voting for the other guy, ask that person, why do you think he won't release his tax returns," Clinton said. "Just asking. I think it is a question he should have to answer."

Clinton has relished going after Trump, especially to receptive audiences like those at union events.

To close the event, Clinton questioned whether Trump supporters event know what the presumptive Republican nominee stands for and added: "America is better than Donald Trump."